1. Field of the Invention
The invention generally relates to an electronic apparatus, a display driving apparatus, and a digital content display method thereof, and more particularly, to an electronic apparatus, a display driving apparatus, and a digital content display method thereof with a digital content protection mechanism.
2. Description of Related Art
In this information era, communication networks deployed across the world not only provide a convenient communication channel but also allow people to download network resources, play digital videos, or even read e-books through electronic apparatuses at anytime and anywhere. These communication networks make today's life more interesting and colourful and provide a very convenient way for people to exchange information.
In order to avoid any copyright related issue (for example, unauthorized copy, use, or distribution of data) that may arise when network resources are downloaded through electronic apparatuses, how to protect digital contents available online has become one of the major subjects to electronic product manufacturers.
Since digital contents are easily copied and distributed, a digital rights management (DRM) technology for protecting digital contents has been developed recently. In short, a DRM technique is to encrypt a digital content and restrict the distribution channel thereof by only allowing authorized electronic apparatuses to access it. In other words, both the play and transmission of a digital content protected by the DRM mechanism are restricted to a certain extent. Thereby, the copyright of the digital content is protected and the digital content is prevented from being misappropriated.
In addition, the display driving apparatus of a liquid crystal display (LCD), an organic light emitting diode (OLED) display, or a light emitting transistor (LET) display is usually composed of a source driver, a gate driver, an analog-to-digital converter (ADC), a buck or boost circuit, a digital control circuit, and other analog circuits. Generally speaking, a source driver or a gate driver usually has dozens or even hundreds of channels. Thus, a display driving apparatus can coordinate the control states of the source driver and the gate driver. A large display is usually equipped with a digital set-top box, a built-in video signal decoder chip, or an external video decoder in order to receive continuous video signals. Since an additional chip or device has to be disposed for receiving and display video data, the hardware cost is high. Besides, the decoded video data may be captured before it is sent to the display driving apparatus.
FIG. 1 illustrates a display of a handheld apparatus. Referring to FIG. 1, the display 10 includes a panel body 12 (a LCD panel or an OLED panel), a display driving apparatus 14 (a single highly integrated display driver chip is usually adopted in a small handheld apparatus), and a flexible printed circuit (FPC) 16. The FPC 16 has a connector and a few voltage stabilizing circuits and can be connected with an external central processing unit (CPU), microcontroller, or display chip.
A display driver chip of a handheld apparatus is a highly integrated chip, and which usually includes a source driver, a gate driver, a digital control circuit, a power conversion circuit, and a digital-to-analog converter (DAC). All of foregoing circuits are integrated into a single chip.
FIG. 2 is a diagram of a handheld or non-handheld apparatus. Referring to FIG. 2, a special encryption/decryption chip 20 is disposed by the manufacturer to display a protected digital content. The encryption/decryption chip 20 increases not only the hardware cost but the power consumption and surface area of the handheld apparatus 10. In addition, decoded data may be easily captured between the external CPU 30 and the display by an external device. Thus, the digital content to be displayed may be misappropriated. This is because the signals and communication information to be sent by the CPU or display chip to the driver chip of the display are usually not encrypted. Even if an encrypted data is sent, the data is usually encrypted in an encryption format common to the industry and a corresponding decryption method can be easily obtained from a manufacturer.
If no additional encryption/decryption chip is disposed and instead, the encryption algorithm is written into a program in the CPU, the operation load of the CPU is increased, and the software encryption algorithm in the CPU may be easily cracked by a reversed engineering technique. Besides, as described above, the decoded data may be captured between the external CPU and the display by an external device. Thus, digital contents cannot be effectively protected.